Merge pull request #4388 from GeoffreyBooth/import-member-named-default

Allow imported module members to be named `default`

Author: lydell

lib/coffee-script/grammar.js

@@ -372,6 +372,8 @@ grammar =
   ImportSpecifier: [
     o 'Identifier',                             -> new ImportSpecifier $1
     o 'Identifier AS Identifier',               -> new ImportSpecifier $1, $3
+    o 'DEFAULT',                                -> new ImportSpecifier new Literal $1
+    o 'DEFAULT AS Identifier',                  -> new ImportSpecifier new Literal($1), $3
   ]
 
   ImportDefaultSpecifier: [
@@ -409,6 +411,7 @@ grammar =
     o 'Identifier',                             -> new ExportSpecifier $1
     o 'Identifier AS Identifier',               -> new ExportSpecifier $1, $3
     o 'Identifier AS DEFAULT',                  -> new ExportSpecifier $1, new Literal $3
+    o 'DEFAULT',                                -> new ExportSpecifier new Literal $1
   ]
 
   # Ordinary function invocation, or a chained series of calls.

lib/coffee-script/lexer.js

@@ -121,7 +121,7 @@ exports.Lexer = class Lexer
         @tokens[@tokens.length - 1][0] = 'IMPORT_ALL'
       else if @value() in COFFEE_KEYWORDS
         @tokens[@tokens.length - 1][0] = 'IDENTIFIER'
-      if @tag() in ['IMPORT_ALL', 'IDENTIFIER']
+      if @tag() in ['DEFAULT', 'IMPORT_ALL', 'IDENTIFIER']
         @token 'AS', id
         return id.length
     if id is 'as' and @seenExport and @tag() is 'IDENTIFIER'

lib/coffee-script/parser.js

@@ -685,3 +685,51 @@ test "default and wrapped members can be imported multiple times if aliased", ->
       foo as bar
     } from 'lib';"""
   eq toJS(input), output
+
+test "import a member named default", ->
+  input = "import { default } from 'lib'"
+  output = """
+    import {
+      default
+    } from 'lib';"""
+  eq toJS(input), output
+
+test "import an aliased member named default", ->
+  input = "import { default as def } from 'lib'"
+  output = """
+    import {
+      default as def
+    } from 'lib';"""
+  eq toJS(input), output
+
+test "export a member named default", ->
+  input = "export { default }"
+  output = """
+    export {
+      default
+    };"""
+  eq toJS(input), output
+
+test "export an aliased member named default", ->
+  input = "export { def as default }"
+  output = """
+    export {
+      def as default
+    };"""
+  eq toJS(input), output
+
+test "export an imported member named default", ->
+  input = "import { default } from 'lib'"
+  output = """
+    import {
+      default
+    } from 'lib';"""
+  eq toJS(input), output
+
+test "export an imported aliased member named default", ->
+  input = "import { default as def } from 'lib'"
+  output = """
+    import {
+      default as def
+    } from 'lib';"""
+  eq toJS(input), output